public function run() { echo 'I run fast'; } private function drive() { echo 'I drive a car'; } } class Son extends Dad { public function goToSchool() { echo 'I go to school'; } public function whatIsMyName() { echo $this->name; } } $son = new Son('Nick', 'Long'); $son->run(); //will output I run fast $son->goToSchool(); //will output I go to school $son->drive(); //produces an error $son->whatIsMyName(); //will ouput Nick